Recorder



Dec. 14, 1965 R. s. KAMPF 3,222,945

RECORDER Filed Jan. 12, 1962 4 Sheets-Sheet 1 FIG JNVENTOR. RICHARD S. KAMPF ATTOR N EY.

Dec. 14, 1965 R. s. KAMPF 3,

RECORDER Filed Jan. 12, 1962 4 Sheets-Sheet 2 INVENTOR. RICHARD S. KAMPF ATTORNEY.

Dec. 14, 1965 R. s. KAMPF 3,222,945

RECORDER Filed Jan. 12, 1962 FIG. 3

hii ill A B I BC :LL: '5'

I H l5 D INVEN RICHARD 8. KA

ATTORNEY.

4 Sheets-Sheet 3 I Dec. 14,1965

Filed Jan. 12, 1962 R. s. KAMPF 3,

RECORDER 4 Sheets-Sheet 4 F l G. 5

INVENTOR.

RICHARD S. KAMPF United States Patent Gil ice 3,222,945 Patented Dec. 14, 1965 3,222,945 RECORDER Richard S. Kampf, Denver, Colo., assignor to Honeywell, Inc., a corporation of Delaware Filed Jan. 12, 1962, Ser. No. 165,916 6 Claims. (Cl. 74-200) This invention relates to recorders and, more specifically, to oscillographic recorders in which a record or trace is made by means of a pencil or beam of radiant energy which falls upon the surface of a long strip or sheet of sensitized recording material, such as paper, so as to form a trace or record thereon. Such strips or sheets of recording material are driven from a supply roll to a take-up roll by means of a motor, such as an electric motor. The speed of the recording sheet may he suddenly increased by operation of push buttons controlling the transmission of power to the supply roll to the roll of paper or to the take-up roll.

The transmission disclosed herein comprises an input disc, an output disc, and an intermediate wheel bearing on said discs and mounted so as to move away from the axis of one and towards the axis of the other so as to vary the speed and the torque with which the input disc drives the output disc. This transmission drives the spool on which the recording medium is taken up. In order to obtain satisfactory acceleration of the take-up spool, it is necessary to restrict the motion of the intermediate wheel by means of a suitable damping device. Accordingly, it is an object of this invention to provide such a damping device.

If the transmission shown herein is called upon to accelerate the take-up spool for the recording medium suddenly, if the damping control shown herein is not used, the transmission will immediately shift down to a lower speed and higher output torque to accommodate the apparent increase in load it looks into by reason of the inertia encountered when attempting to accelerate the take-up spool to the higher speed. Under these conditions, the take-up spool does not take up paper as fast as the recording medium is being driven, and consequent'ly paper balloons out in front of the machine. The damping device shown herein reduces this effect by preventing the self-adjusting, variable-speed unit from shifting down rapidly when suddenly applied loads are encountered. It is a further object of this invention to provide damping means whereby the intermediate wheel of the transmission disclosed herein may spiral toward the input shaft. Consequently, a rapid reduction in the speed of the output shaft is prevented when a suddenly applied load is encountered.

Still a further object of this invention is to provide a transmission having power transfer such that equilibrium conditions may be established with a constant torque at any speed within its range. In other words, output torque is constant and independent of speed.

Still another object of this invention is to provide a reverse operation, whereby, if the power transfer is reversed so that the output disc becomes the input disc, and vice versa, the power output from the input disc shown will be constant and independent of speed.

A better understanding of the present invention may be had from the following detailed description when read in connection with the accompanying drawings, in which:

FIG. 1 is a top or plan view.

FIG. 2 is a vertical section on line 22 of FIG. 1 as viewed in the direction of the arrows.

FIG. 3 is an end view with parts broken away.

FIG. 4 is a diagram in end view similar to FIG. 3, with parts in another position.

FIG. 5 is a longitudinal cross section of the damping device.

The recorder of this invention includes a stationary frame 1 in which the various moving parts of first and second transmission devices are mounted. The first transmission device 1a carries on it an output element such as a pulley P which drives the recording medium or spool of an oscil-lographic recorder. Output shaft 2 of the transmission 1b is mounted in frame 1 by suitable bearings and carries, at its right end, output disc 3 which has on its working face a disc facing 4 of a material similar to cork. The output shaft 2 drives the take-up spool of the recorder.

Input disc 6 is mounted on input shaft 8 which is the input to transmission 1b from another output of transmission la, and is suitably mounted in bearings in frame 1. Input disc 6 carries a disc facing 7 and has a portion of its face parallel to and overlapping with a portion of the face of output disc 3.

Between the output disc 3 and the input disc 6 ismounted an intermediate wheel, generally indicated 15. Portions of the rim of intermediate wheel 15 engage with the working face of the output disc 3 and with the working face of the input disc 6. Wheel 15 thereby transmits motion from one disc to the other disc.

The axis of input shaft 8 forms the pivot about which intermediate wheel 15 rocks. On shaft 8 is mounted a bell crank lever, generally indicated 9, and having arms 21 and 22. Arm 21 has attached to one end of it a perforated support 23 which carries one end of an intermediate shaft 14. The other end of the support 23 is fixedly mounted to the bell crank lever 9 for movement therewith. Intermediate wheel 15 is movable axially and in rotation about shaft 14. Intermediate wheel 15 comprises a ring 16 of rubber or light asphalt material. Portions of ring 16 contact the surfaces of discs 3 and 6. A generally flat, leaf spring 1 0 is secured by means of a plate 11 to lever 9. The right hand end of spring 10 is forked so that it passes under the head of a screw 12 mounted on a stationary portion of frame 1. A coil spring 13 bears, at its lower end, against a nut 23' and, at its upper end, against the under side of spring 10. Lever 9 is biased for counter-clockwise movement around shaft 8 by spring 10.

Arm 22 of lever 9 carries at its end a screw 20 which may engage, at its lower end, with .a piston rod 28 mounted in a cylinder 27 carried by frame 1. Piston rod 28 and cylinder 27 form parts of a damping device. Spring 13 is a means for holding the end of spring 10 under the head of screw 12. This provides for lateral mo tion of spring 10 during bending.

Intermediate wheel 15 is clamped between output disc 3 and input disc 6 by means of a flat spring 17 which abuts, at its center, against a thrust bearing 18 on shaft 2, and at its opposite ends, adjustably against frame 1, by means of screws 18a.

Alternatively, bell crank lever which carries intermediate wheel 15 may be mounted on a shaft whose axis may or may not coincide with the axis of input shaft 8. The axis of this shaft, however, must lie in the plane defined by the axis of output shaft 2 and of input shaft 8.

The operation of transmission 1b can best be seen from FIGS. 3 and 4. FIG. 3 shows the device in its normal, unloaded position. At that time, output disc 3 tends to run at its maximum speed. FIG. 4 shows the device in its loaded position. In its loaded position, intermediate wheel 15 is urged against a stop 19 on shaft 14. A line A connects the axes of output shaft 2 and of input shaft 8 of transmission 1b. The path of travel of path of intermediate wheel 15 on output disc 3 is represented by a curve D. C represents the plane of intermediate wheel 15. B is a line tangent to the path of contact D between the intermediate wheel 15 and the output disc 3. When the axis of shaft 14 is above the line A, as seen in FIG. 4, there is an angle BC between the, lines B and C. Intermediate wheel 15 therefore tends to follow spiral path D on output disc 3 and to travel away from. shaft 2 and to travel toward shaft 8 as the transmission 1b is loaded. Intermediate wheel 15 is then urged against stop 19 on shaft 14 and the speed of rotation of output disc 3 is at a minimum, the torque then being a maximum. Angle BC is usually not very large, depending on the ad justment of screw 12 which determines the bias of spring and the torque required to rotate shaft 14 about pivot 8.

. Upon the assumption that a load is placed on the output pulley P; disc 3 will tend to slow down and present a higher reaction load to intermediate wheel 15. The input disc 6 will roll intermediate Wheel on output disc 3. This causes shaft 14 to pivot about the center of shaft 8 until the axis of shaft 14 is above the line A, as seen in FIG. 4. In this position an angle BC is formed between plane C of wheel 15 and tangent B to the path of contact D which intermediate wheel 15 makes with the outpnt;disc-3.. Thiscauses intermediate wheel 15 to walk away from output shaft 2 and towards shaft 8 on a spiral path. As this happens, the speed of shaft 2 is reduced with a consequent increase in torque. In actual practice, shaft 14 will continually seek an equilibrium position so that the output torque and speed match the load. The threshold where the transmission starts to shift away from shaft 2 and towards shaft 8 is determined by a bias spring 10. The type of response can be controlled varying the bias of spring 10; i.e., by having a spring rate increasing, decreasing, or constant.

In the transmission (described above) means are provided for damping the transmission against a sudden application of power. On the other hand, the damping device presents little restriction to slowly applied loads and allows the transmission to shift as necessary.

The damping device consists of a fixed metal cylinder 27 as shown in section in FIG. 5. A closely fitting piston 28 slides in the cylinder. A silicone damping fluid (Dow Corning) having a high viscosity (approximately 100,000 centistokes) fills the annular area between the piston and the cylinder. A very thin film of this fluid is retained in the entire annular space between piston 28 and cylinder 27 by capillary attraction. The fluid extends for the full length of the annular space between the piston and the cylinder. Consequently very appreciable forces can be developed as attempts are made to put the fluid in shear. The forces that result from attempts to shear the fluid are a function of the velocity of piston 28. That is to say, very high forces are required to move the piston at a high velocity and very small forces will move the piston at a very low velocity. A ring 31 is fixed to and moves with piston 28. Ring 31 also serves as .a shoulder for the left end of return spring 30. As piston 28 is moved to the right, spring 30 is compressed. When the load is removed from the piston 28, spring 30 will push piston 28 back to its original position in which ring 31 engages the cylinder 27. The right end of spring 30 bears against block 29 which retains and centers the spring 30 at the right end of the cylinder 27. The retainer ring 32 holds block 29 in place. A felt washer 33 is secured to the left end of cylinder 27 by means of adhesive. This felt washer 33 is simply a dust cover.

The cantilever spring 10 controls the speed-torque relationship of the transmission. Coil spring 13 holds leaf spring 10 under the head of screw 12 and allows for adjustment of the bias by turning screw 12. This allows lateral motion of spring 10 under the head of screw 12 when spring 10 bends. Screw permits adjustment of the clearance between arm 22 and the damper piston. 28.

Bell crank lever 9 is pivoted on shaft 8 and supports intermediate shaft 14 so that intermediate shaft 14 pivots from one side of the line connecting the centers of discs 3 and 6 to the other side of said line. As a load is applied to the output disc 3, shaft 14 tends to swing in a direction forcing screw 20 down on piston 28. The rate of motion of screw 20 and, consequently, of shaft 14, is then restricted by the damping action of piston 28. This, in turn, greatly reduces the rate at which the intermediate wheel 15 may spiral towards the input shaft 8, and, consequently, a rapid reduction in the speed of the output shaft 2 is prevented when a suddenly applied load is encountered.

What is claimed is:

1. A self-adjusting inertia activated, variable-speed transmission including, a frame, a rotatable input disc pivotally mounted in said frame, a rotatable output disc having a face portion partially overlying and substantially parallel with a portion of the face of said input disc, a shaft, an intermediate wheel, the wheel being mounted for slidable rotatable movement along the shaft by inertia when the speed of one of the discs is altered and having a portion of its surface engaging said input disc and a portion of its surface engaging said output disc, a crank arm, one end of the crank arm being positioned to pivotally support one end of the shaft in a position to effect movement of the longitudinal axis of the shaft from one side of a line connecting the centers of said discs to the other side of said line, and a damping device operably positioned to contact the other end of the crank arm to delay the movement of the shaft and the inertial movement of the intermediate wheel therealong in the direction which causes the wheel to move towards the center of said input disc when the speed of rotation of one of the discs is altered.

2. The transmission defined in claim 1, wherein the damping means is comprised of a fixed cylinder, a piston closely fitting in said cylinder, the piston being positioned for contact by the other end of the crank arm when the speed of one of the discs is altered and silicone damping fluid having high viscosity filling the annular space between said piston and said cylinder.

3. The transmission defined in claim 1, wherein the damping means is comprised of a fixed cylinder, a piston closely fitting and sliding in said cylinder, a damping fluid having a high viscosity filling the annular space between said piston and said cylinder, and a spring biasing said piston for movement in one direction in said cylinder.

4. A transmission as called for by claim 1, including, a fixed cylinder, a piston closely fitting and sliding in said cylinder, a damping fluid having a high viscosity filling the annular space between said piston and said cylinder, a spring biasing said piston for movement in said cylinder, and a ring fixed to said piston and serving as a stop to limit the travel of said piston relative to said cylinder in one direction and also serving as a shoulder for said spring.

5. A self-adjusting, variable-speed transmission, including, a frame, an input disc mounted for rotation in said frame, an output disc mounted for rotation in said frame and having a face portion thereof partially overlying and substantially parallel with a portion of the face of the input disc, a shaft on said frame, a bell-crank lever pivot, ally mounted on said shaft, an intermediate shaft mounted on said bell-crank lever, an intermediate Wheel mounted for axial and rotary movement on said intermediate shaft, a ring forming part of said intermediate wheel and having engagement at its outer circumferential surface with a portion of said input disc and with a portion of said output disc to effect axial movement of the ring along the intermediate shaft and movement of the central axis of the intermediate shaft from, one side of a line connecting the centers of the discs to the other side of said line during the occurrence of a change in the speed of said discs, a coil spring biasing said bell-crank lever for rotation about said first-mentioned shaft in one direction, a cylinder fixed in said frame, a piston closely fitting and sliding in said cylinder, a damping fluid having high viscosity filling the annular space between said piston and said cylinder, a spring biasing said piston for movement in said cylinder, a ring fixed to said piston and serving as a stop to limit the travel of said piston relative to said cylinder in one direction and also serving as a shoulder for said spring, and an adjustable means on said bell-crank lever for limiting the amount of travel through which said bell-crank lever is required to move before it overcomes the bias of said coil spring and it is brought into contact with the piston during the occurrence of the change in the speed of one of the discs.

6. A self-adjusting, variable-speed transmission, including, a frame, a rotatable input disc pivotally mounted in said frame, a rotatable output disc having a face portion thereof over-lying and substantially parallel to a portion of the face of said input disc, an intermediate wheel having a portion of its surface engaging said input disc and a portion of its surface engaging said output disc, means mounting said intermediate wheel for movement of its central longitudinal axis from one side of a line connecting the center of said discs to the other side of said line, and a damping device spaced from the wheel mounting means to effect a delay in the movement of said mounting means and intermediate wheel thereon while the intermediate wheel is moved towards the center of said input disc upon an increase in the speed of one of the discs, said damping device increasing its resistance to the movement of said mounting means and wheel as the speed of the movement of said last-mentioned disc increases and the mounting means is brought into contact with the damping device.

References Cited by the Examiner UNITED STATES PATENTS 924,913 6/1909 Mellen 26734 1,061,537 5/1913 Gruss 26734 1,572,060 2/ 1926 Yarnall 26734 2,157,065 5/1939 Madle 74190.5 2,669,325 2/1954 Raines 188100 2,917,943 12/1959 Neilsen 74190.5

DON A. WAITE, Primary Examiner.

BROUGHTON G. DURHAM, Examiner. 

1. A SELF-ADJUSTING INERTIA ACTIVATED, VARIABLE-SPEED TRANSMISSION INCLUDING, A FRAME, A ROTATABLE INPUT DISC PIVOTALLY MOUNTED IN SAID FRAME, A ROTATABLE OUTPUT DISC HAVING A FACE PORTION PARTIALLY OVERLYING AND SUBSTANTIALLY PARALLEL WITH A PORTION OF THE FACE OF SAID INPUT DISC, A SHAFT, AN INTERMEDIATE WHEEL, THE WHEEL BEING MOUNTED FOR SLIDABLE ROTATABLE MOVEMENT ALONG THE SHAFT BY INERTIA WHEN THE SPEED OF ONE OF THE DISCS IS ALTERED AND HAVING A PORTION OF ITS SURFACE ENGAGING SAID INPUT DISC AND A PORTION OF ITS SURFACE ENGAGING SAID OUTPUT DISC, A CRANK ARM, ONE END OF THE CRANK ARM BEING POSITIONED TO PIVOTALLY SUPPORT ONE END OF THE SHAFT IN A POSITION TO EFFECT MOVEMENT OF THE LONGITUDINAL AXIS OF THE SHAFT FROM ONE SIDE OF A LINE CONNECTING THE CENTERS OF SAID DISCS TO THE OTHER SIDE OF SAID LINE, AND A DAMPING DEVICE OPERABLY POSITIONED TO CONTACT THE OTHER END OF THE CRANK ARM TO DELAY THE MOVEMENT OF THE SHAFT AND THE INERTIAL MOVEMENT OF THE INTERMEDIATE WHEEL THEREALONG IN THE DIRECTION WHICH CAUSES THE WHEEL TO MOVE TOWARDS THE CENTER OF SAID INPUT DISC WHEN THE SPEED OF ROTATION OF ONE OF THE DISCS IS ALTERED. 